1. Field of Invention
This invention describes a computer controlled device, having several independently controlled storage vessels, for trapping various types of gases.
2. Description of Prior Art
There is a need for a computer controlled device which can collect multiple gas samples in sequence. There are many types of gas traps in the prior art, but none have these characteristics. Most prior art gas traps are intended for very specific tasks such as gas chromatography (Kunsman et al.; U.S. Pat. No. 3,731,466; 1973), crude oil detection (Ortega et al.; U.S. Pat. No. 5,408,868; 1995), distribution of corrosion inhibitors in gas (Johnson et al.; U.S. Pat. No. 4,615,387; 1986), or trapping gases released specifically from mud (Wright et al., U.S. Pat. No. 5,199,509; 1993). Finally, the inventions of Benedict (U.S. Pat. No. 3,859,808; 1975) and Benedict et al (U.S. Pat. No. 5,859,807; 1975) describe a trap used in the processing of uranium hexafluoride. These devices have very specific structural features, different from those of the current invention, which make them unsuitable for general laboratory gas collection and analysis.
Another class of traps is intended to capture certain gases for later disposal. Storage of samples is not the aim of these inventions. For example, the "automatic gas trap" of Lenfant (U.S. Pat. No. 3,677,279; 1972) collects undesirable gas accumulations in liquid filled chambers. The patent by Gladon (U.S. Pat. No. 4,365,659; 1982) describes a trap intended to remove atmospheric pollutants by bubbling air through a chemically active solution, and the patent by Caton et al. (U.S. Pat. No. 5,503,558; 1994) describes an invention relating to traps and filters for removing gaseous materials from exhaust gases of semiconductor manufacturing equipment. Finally, the patent by Boissin (U.S. Pat. No. 3,712,074; 1973) describes a cryogenic trap for removal of gases from a chamber. None of these inventions is a gas sampling apparatus capable of storing a series of independent, individual, samples.
Some industrial gas traps seek reuse of recovered gases. For example, the gas trap by Missimer (U.S. Pat. No. 5,261,250; 1993) describes a two stage apparatus capable of recapturing vapors lost during various industrial processes. Here, there is no interest in storing numerous samples, or in computer control, only bulk recovery of volatile substances. The invention by Worden et al. (U.S. Pat. No. 5,228,514; 1993) describes a gas trap which captures volatile gases by cooling and then releases them later by heating for later analysis. However, the Worden apparatus, which has a very different structure than the present apparatus, has no capacity for, storing multiple samples or computer control.